Let your gothic imagination run wild in Pembrokeshire

In the past, when I went on holiday to Pembrokeshire, I used to seek out the more pleasant spots: safe, sandy beaches in sheltered bays, open countryside with beautiful views, pretty pubs in idyllic little villages where you could sip local ale and watch the sun go down on an evening. Now it's all changed.

Today, when I set out on a break out west, I spend my time on the lookout for sinister locations: rocky beaches where it's dangerous to swim because of the strong currents; high clifftop paths where you could easily slip and fall; moors dotted with abandoned mineshafts that could swallow you up for ever, should you have the misfortune to step on them. No, I'm not trying to bump off any members of my family. It's simply that I've started to write thrillers, and I'm constantly searching for good places to kill off my characters.

As any mystery writer, published or unpublished, will know, this is one of the hazards of taking to crime. On holiday, you're not the slightest bit interested in going anywhere relaxing, peaceful, or friendly. Instead, you find yourself forcing your companions to visit godforsaken, windblown spots in search of the perfect location to commit violence.

But if you can persuade them what fun this will be, it's not a bad way to plan a holiday itinerary. And there are few places in Britain that are more suited to such a task than Pembrokeshire, West Wales, where a stunning landscape of mountains, beaches, forests and moors allows the gothic imagination to run wild.

I've been visiting Pembrokeshire off and on for the last 20 years, so when it came to writing my crime debut, The House on the Cliff, I chose to set the more sinister parts of it there. The location of the house in the novel is based on The Druidstone Hotel, overlooking St Bride's Bay. It's a breathtakingly beautiful spot, with views far out into the Atlantic, and has been a popular bohemian haunt for many years.

You can stay in the hotel proper (where families are catered for with high tea served for children early in the evening), or book one of the self-catering cottages clustered around the hotel. On New Year's Eve, there's always a big party with fireworks and live music. Next day, a walk on the beach will blow your hangover away.

While the location of The Druidstone was perfect for my novel, I used a bit of poetic licence when describing the house. In reality the building is a large, handsome farmhouse made of local stone. In my novel, it's transformed itself into an elegant Jacobean pile, of which there are some stunning examples in Wales (notably at Plas Teg, in the north, which runs "paranormal" nights, aka ghost hunts).

Similarly, I thought the real beach at The Druidstone a little too safe, sandy and idyllic for my purposes, so I swapped it for a much more sinister one at Dunraven Bay, on the Welsh coast of the Bristol Channel. This is an extraordinary place, a rocky cove pitted and turreted like the surface of the moon. A geologist's paradise and a swimmer's nightmare, it's only accessible by steep steps, and you can easily get cut off by the tide and stranded there.

I've only ever looked down on Dunraven Bay from the walled gardens above it, swept by the salt wind but still tended. These, too, are well worth a visit; they're free of charge, sheltered and secluded (good for cricket games and picnics in the summer). The gardens are all that remain of Dunraven Castle, a mansion demolished in the sixties, whose single remaining tower gives the place a slightly eerie feel.

Back to Pembrokeshire, and I've earmarked a few choice locations for skulduggery in future novels. First, the West Blockhouse near the pretty little beach at Dale. This is a 19th-century fort built out into the sea with the most fantastic views you could imagine, especially at night when an array of spooky lights over Milford Haven harbour make the landscape look like something Tolkien, or perhaps Roger Dean, might have dreamed up. The thick walls give the place a sombre feel, almost like being in a dungeon, albeit a very comfortable one with delightful sea views. The fort is available for bookings from the Landmark Trust.

Also in Dale is a memorable B&B, Allenbrook, a lovely old country house that features comfortable rooms, delicious breakfasts, and peacocks strutting about on the lawn.

The blue lagoon at Abereiddy is another promising spot for dastardly deeds. An abandoned slate quarry that's been flooded by the sea, it's more than 20 metres deep, and the water has taken on a strange, greenish hue.

Moving on from the perils of the natural world, St David's Cathedral has always attracted me as a possible site for dark deeds. The place is full of surreal carvings, notably underneath the wooden misericords or "mercy seats", on which the clergy rested their backsides during long services. Here, you can see rude pagan graffiti carved by medieval craftsmen, mocking their pious brethren. An unusual place to have someone kick the bucket, I feel. Murder in the cathedral, anyone? Finally, for a really strange setting I might venture into the Gwaun valley, where people celebrate New Year on 13 January, according to the ancient Julian calendar. At the one-room Dyffryn Arms, known as Bessie's pub, the landlady pours your pint of real ale from a jug, and serves it through a hatch. The room is sparsely furnished, in the style of the 1940s. It's like being in a time warp. A dark, mysterious one – and the perfect place to start another story.

The House on the Cliff by Charlotte Williams is published by Macmillan, priced £16.99

Travel essentials

Staying & seeing there

The Druidstone Hotel, St Bride's Bay (01437 781221; druidstone.co.uk). Doubles start at £110, B&B.

Plas Teg Country House, Mold (01352 771335; plasteg.com). Guided tours £7. Paranormal nights cost £40pp.

West Blockhouse, Dale (01628 825925; landmark trust.org.uk). Four nights from £387. Sleeps eight.

Allenbrook B&B, Dale (01646 636254; allenbrook-dale.co.uk). Doubles start at £80, B&B.

St David's Cathedral (01437 720202; stdavidscathedral.org.uk).

Dyffryn Arms, Bryncoch (01639 636184; thedyffrynarms.com).

More information

visitpembrokeshire.com